Rheostat.



o.. R. MESTON E H, I. 39mm,

(RHBOSTAT. APPLICATION 4FILED APR. 213.1909.

w/TNESSES l l k tra@ OllllllOE.

lNC'l'l, Ol" ST. LOUIS, MISSOURI, ASSIGNORS TO EMER- SON lLECTlllC MANUFAGTURNG COMPANY, OF ST. LOUIS, MISSOUR, A CORPORATION Ol" MISSOUR.

BHEOSTAT.

No. Qrfdl. .Specification of Letters Patent. Patented .Tilly 20, 1909.

application filed April 28, 1909. Serial No. 491,687.

To all wama 'it 'may coment:

ij@ it known that we, @nantes lt. lulnsToN and lli-:runner l.. Fin on, citizens oi' tlie United @www 5,11 r @gf i .Y u Afm, 1 1 n i.i....ts, notant, .it i, Meurs, nssoarn lax t invento!! a certain new and useful Improvein lllieostats, of Wliieli tlie following is a lull, :l :nid e1' yitt description, suoli as will enable others skilled 1n the art Vto WluelL it appertains make and use tlu saine, reference beine, lnnl to ille accompanying drawings. farming nait of tliis speci'l'ieation, in wl1iel1 I Figure 1 is a plan or top View of a rlieostztt of our improved `Lmotion; Fig. 2 is a Le under side of the section taken on l s a plan. view i' ie resistance wire agi-animatie View illusof titre rlieostatu 1 Vion relates to rlreostats or the type usually employed on electric. motors, the objeit el our inventien being to construct snnple, compact rneo tnflneli may be t v.,fuerl to motors, the resistance lr rlreostut are formed and arf tnat they are thoroughly ventiand air-cooled thereby preventing e tlie aber;

i. e purposes, our invention oonin a suitable b se of insulation in Wliieli. ined one or more peri receive tire resistance wire, tnt el eontait points provider li Uontaet points are A i to le line and resistame wires, and were eontaot handle pivotally .mounted en trie base and adapted to engage the eontaet points.

lieferringby ni'nnerals to tire aecompanying drawings, 1 designates tire baseof the rlleostat, which is preferably in the forni of a disk of porselein or analogous insulating ina-- terial, and formed tlireugll said disk adjacent its a pair et eppositely arranged apertures, which reeeiife sere or like fastening devi l utilized for attaching tlie rlleos tat to vthe motor. Formed in. 'the under side of the base 1 a rectangular recess :5, and termed. through the center the base is alarga aperture The members wliielr receive the resistance frire @emprise a pair of reetangan eonnertons and the.

i lar plates 5 ol suitable insulation, which are of suoli size as to snugly lit Within the aper- 55 ture 3, said plates being spaced apart byY means of strips 6 of insulation arranged between the side edges of said plates and the ends of said strips occupying suitably formed recesses 7 arranged at the corners of the re- 60 cess 3. The plates 5 are each provided with a series of perforations 8, and the perforations of one plate are preferably staggered or oil-set relative to the perforations in the pposite plate. anee eoils is Wound upon the plates in such a manner as to leave a slight space between the eonvolutiens of tlie Winding, and said construction, together with the perforations permits air 'to pass between the coils and 70 between. the plates, thereby permitting a free radiation of the heat generated in the coils While the same are in use, `and consequently maintaining a comparatively W degree of temperature in said rheostat. The

plates 5 are held in position in the recess 3 by means of washers 10, the same being leeated beneath nuts 11, which in turn are arranged on tlie tlireaded'ends of screws or boltsv 12, which pass through apertures eess 3.

Fixed in any suitable manner on top ofthe base l. and above tlie opening 4 is a platel., te Wluoli is pivotally connected gne end of-xa ContactA handle 13, the same extending across the top of the base 1 and beingadfp't- .ed to engage upon any one of a serles'of con.u

tact onits 14, 1a lab and 14C. L11 s 15 are formed integral with the top of tlrebase 1 90 adjacent tl'ie ends of this series of eontaet points, and Whieli lugs act as sto s to limit the swinging movementof the andle 13. One end of the Wire 9 which formsy the resist` ance coils is connected to the oontaetpoint le, the opposite end of said Wire being coni' nested to the Contact point 14. Connecting',- the Contact point 141D with the wire 9 at; sin

intermediate point, or at a., point betweenV the plates 5, is a'short Wire 16 which in tlie `100 resent -instance is located. in a groove' 17v termed in the under eide of the base 1 being y embedded in a suitable insulating 'cement er f compound which dlls said groove.` One 'terminal of the main line or conductor is voon-- 1051,.. nested to a binding post 18 locatedV on the The Wire 9 forming the resist- 65 formed 80 through base 1, adjacent the sides of the replate 13, and she opposite lveririinzil ol this main. line or conductor is connected ino :i binding post 19 suite/bly loc/filed ou 4rho has@ 1. Loading 'from this binding poet 19 lo 'the Contact point 14C ik: :i Suitable cohihicloi 20.

Wheie a rhoosl'zit eo constructed is userl uDon im. ordinary motor, for insmico au.

is not in service. shl'lted ou the coiilaelv-pouit (lle is 'shifted on 'to 1che cominci 'point fY half of the resist/mice is cui; oui, owin connection 16, whicl'i loods 'from met point Mb to o, point :ipproximsilo? way be''vveen the ends el the Wire lornfiing the resistance. llfheii the handle i, shil'leil on to the point 14C, the entire resistance out out and the l'ull power of the Current passes from the terminal connected to the binding-post .l-E, through the pleito il, haw (lle 13, Contact pointy il, conrhicor 2G, :ii-hl from thence to the line conductor f-.oimoclhig to the bindingepost E9.

A rlieostzit ol' our improved cmismction is comparatively simple. coiiipriees :i mini mum number oVA parte, is 'Very cannoni; mi can therefore he oalvantngeously {im} wyefi in connection with. zLl. forms ol' mail elo/vizio mobors, and as the rc ismicc ci are velitileted mul therefore Lir-coole l, ho heh?y genemied in the coils ol' Ache rhcoszzilfie remlily radiated and. disseminated,

Ne claim:

1. in e rheostat, :1. hose in which is a recess, e plurality oi perioiiiied pluie; mevzibly positioned in recess, in. Y Wherehy said Qlm'vee hold spaced fi'pmiz, and a resista-nce Wire wound upon seid plates.

2. In rheosatj o, hose ih whiel. a recess, e plurality of performed p mevzihly positioned iii reces plates ere spaced e; wt, :i resiy wound upon seid. platee, and

ill-:armed miie i, i the line is operi emi therefore the resistance i lllheu the houille 13 l lille oniire resistfmco is in service, and. when sin l .spaces l winding of said reeisvtim'ice Wire.

l 3. lil n, rheosmt, :i huso through which is g A[owned in opening, there heilig :L perforated plaie applied to he ha.; over seid. opening, 21, rosistahce wire wound upon seid plete, sind f there hemp; Simcoe l'ormefl between the con g volucions ol the winding ol seid roi'tzuice Wire.

I 4;. lx1 e rlieoelziu, a, brise Johrough which is formed im o'enn'ig, a plurality oi' herloroml. l

plaies rei'iiovizhly' posiiionenl on che plete which plaies are spaced.

mi@ e. resistance wire Wound upon y over 25ml opening,

kl 5. lh :Jh nimmt, :i Vhorse through ii'hich med 5.1i opening, i ['ilureli'lvy ol' perloriilml i remiwiihly positioned ou the philo over said opening, which plaies are :sg'imcal apn l1, i1. resistance Wire wound when :siiifl plates, mail hoL being simi-.es formell hw tween ilie unifi-lotions ol' tho winding ol' said. resistance wire. i

lil rhoofst-zit, e hase iii Whioh. formell recess, lhere/ being an oi'iehhig l'oimcd Lhioiigh. the hase coi'iiimmlooting with suiiri reoesS, zL ,iliimliiy el' perforated plaies reii'iovfihly fir posiuio'mil iii "che recess, sparing! vige/ 1 between the omis; o." enfui Simi seid el.' 'comience wire wound Upon plates, 2i hielos. e" lvhor`r heini; l c" see Formed in lim E el the corners el me lirfifmenliohml recess lor che reception elA the :milo ol' i'ho spacing stri; e.

lh iesliimoiiy whereof we hereunto olli); i our signatures iii the presence ol 'iwo will heisses, Lhis lth dey ol' 

